diff --git a/README.md b/README.md
index 94698312..f1190442 100644
--- a/README.md
+++ b/README.md
@@ -17,6 +17,8 @@ Use `drive help` for further reference.
 	$ drive diff [path] # outputs a diff of local and remote
 	$ drive publish [path] # publishes a file, outputs URL
 
+To use your own Google Drive API credentials instead of the built-in credentials, set `GOOGLE_API_CLIENT_ID` and `GOOGLE_API_CLIENT_SECRET` appropriately in your environment before running `drive init`.  See [the Google API docs](https://developers.google.com/drive/web/quickstart/quickstart-go#step_1_enable_the_drive_api) for more information.
+
 ## Why another Google Drive client?
 Background sync is not just hard, it's stupid. My technical and philosophical rants about why it is not worth to implement:
 
diff --git a/init.go b/init.go
index c254fb66..8a57865d 100644
--- a/init.go
+++ b/init.go
@@ -14,11 +14,23 @@
 
 package drive
 
+import "os"
+
+const (
+	clientIDEnvKey = "GOOGLE_API_CLIENT_ID"
+	clientSecretEnvKey = "GOOGLE_API_CLIENT_SECRET"
+)
+
 func (g *Commands) Init() (err error) {
 	var refresh string
-	// TODO: read from env variable.
-	g.context.ClientId = "354790962074-7rrlnuanmamgg1i4feed12dpuq871bvd.apps.googleusercontent.com"
-	g.context.ClientSecret = "RHjKdah8RrHFwu6fcc0uEVCw"
+
+	g.context.ClientId = os.Getenv(clientIDEnvKey)
+	g.context.ClientSecret = os.Getenv(clientSecretEnvKey)
+	if len(g.context.ClientId) == 0 || len(g.context.ClientSecret) == 0 {
+		g.context.ClientId = "354790962074-7rrlnuanmamgg1i4feed12dpuq871bvd.apps.googleusercontent.com"
+		g.context.ClientSecret = "RHjKdah8RrHFwu6fcc0uEVCw"
+	}
+
 	if refresh, err = RetrieveRefreshToken(g.context); err != nil {
 		return
 	}